Don't know about the P90, but I spoke with FosTech about the Echo, and it uses a proprietary bolt carrier to function in an AR. They mentioned some tweaking had been done to get it working with 22LR conversions in the AR, and maybe 9mm conversions, but for now, regular old ARs only. If you could modify that Aug thing to your PS90, you may then have to modify your bolt or carrier or whatever it has to work with the FosTech trigger. If you get that far, let me know, and I'll go buy a PS90 and SBR it right away.

I was actually thinking it would be some type of modified PS90 trigger pack, rather then using the ECHO.

The PS90 uses the same bolt as the P90, and I believe the Gen 2 and 3 trigger packs had that little hammer safety that prevents hammer follow, which is the core part of the Echo trigger that allows it to function.

I think what would be required is designing either the sear or the hammer to fire both when the trigger is pulled, and when it's released.

For those more familiar with the technical aspect of the PS90, does this sound about right?

One shot fired per trigger pull, that's the law. If you fire a shot, and then hammer follow causes another shot to be fired, it's off to the poke with you. From what I've seen of the Binary trigger, hammer following, resulting in a cycling of the charging handle and ejecting of a live round, is a big problem. You say Gen III though, so that may have been fixed, I don't recall what generation they were on when I last looked at them. The Echo has no such problem from what I've seen, but I have hands on experience with neither.

As I understand it, if you somehow depress the trigger and don't want to fire the second shot, engaging the safety will prevent it from firing.

But as most will simply quickly release the trigger upon firing, it's effectively just a very quick double tap.

I think the safety concerns are overblown, and the potential for this system is understated. On the PS90 this would be incredible (shooting 5.x28 at 700rpm) and if you could figure out a way to make it work, you'd be raking in the coin.

Easily sell a few thousand $450 trigger packs, might be worth keeping an open mind.

As I understand it, if you somehow depress the trigger and don't want to fire the second shot, engaging the safety will prevent it from firing.

...

This is the way I understand it as well. Tactical, useful, HD, SD - Nope. Fun as hell - Yep. Because of money, I'd probably not do an AR, P90, ect. But would I do a $475 trigger in a registered SBR lower and stick 9mm and 22LR uppers on it? All day, every day. Did a SlideFire 10/22 recently, full on the most fun in my safe, but the brick of ammo I annihilated means I need to play it cool.

I don't think it's smart, but I think it's silly. Similar to the positive reset triggers

If people would take the effort of making, selling, and buying bullshit products, into pushing legislators and congress to just change the damn thing you're walking around. The world would be a lot better place for all of us, yet I hear almost no talk of it and it's disappointing.

They're SUPPOSED to work for the people. Which every day want more and more suppressed, short, machine guns.

So I'd really like to see someone do something about the actual problem.

This goes in the same bullshit category as bullet buttons, pistol "braces", clipped and pinned lower, striker fire SA smgs. Just shit people put up with rather than fixing the damn problem to get what they want.

Free your second amendment. Remove those BS laws enacted decades ago. This might be the last chance we get. Best not take it for granted.